1. Statement of the Technical Field
The inventive arrangements relate to telematic control systems, and more particularly to an interface for converting human control input gestures to telematic control signals.
2. Description of the Related Art
Robotic systems are growing increasingly common for use in areas in which a human may be subjected to dangerous or otherwise unpleasant work environments. Such applications include explosive ordinance disposal, search and rescue missions, environmental analysis or inspection at toxic sights and the like. These robotic systems are typically controlled remotely. Control units for teleoperation of robotic systems can sense control inputs provided by a user. These control inputs can be measured by one or more sensors and converted into corresponding signals that are transmitted to the robotic system to cause it to move in a desired manner in accordance with the transmitted signals. Similar types of user interfaces can be used for controlling actions in a virtual environment as may be employed in computer gaming and/or simulators.
Simple user interface systems can provide a separately operable control for each movable joint of a robot or robotic manipulator. More complex systems can include hand controllers (sometimes in the form of a pistol grip), which sense the movement by a user's hand. The hand controller generates one or more control signals which are then used for actuating various motion operations of the robot. The control system of the robot will respond to these control signals by activating certain servo-motors, solenoids, or other devices within the robotic manipulator to produce the desired action. Similarly, in the case of a virtual environment, computer software is programmed to respond to signals generated by a hand controller to cause motion in a simulated or virtual environment.
Haptic technology or haptics involves tactile feedback provided by a device to a user. The tactile feedback is typically provided by applying forces, vibrations and/or motions to one or more portions of a user interface device. Haptics are sometimes used to enhance remote control devices associated with machines and virtual reality systems. For example, U.S. Pat. No. 5,831,408 to Jacobus et al. discloses that force feedback systems are sometimes used to communicate forces generated on a robotic hand back to a user, through a hand controller. If the robotic hand impacts an object, the impact is felt by the user's hand. Haptic feedback is commonly used in the computer gaming and simulation field.
In the field of robotics, haptic control systems generally include the ability to sense an absolute position/orientation and direction of movement of a haptic control interface when such movement is initiated by a user. Such absolute position/orientation sensing allows direct correspondence between the position/orientation of a hand control and the position/orientation of a robot device. The absolute position sensing schemes provide acceptable performance, but they inevitably involve use of complex mechanisms, usually including a plurality of gimbals with integrated sensors. The plurality of gimbals and sensors work together to define an absolute position/orientation of a user's hand. However, they also result in a relatively expensive control device and are subject to gimbal lock problems. The gimbals in particular also tend to be somewhat delicate so control devices of this kind are not particularly suited for field deployment.